From patchwork Fri Aug 23 06:32:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Gautam X-Patchwork-Id: 11110649 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 33E2F1395 for ; Fri, 23 Aug 2019 06:33:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 10BB52070B for ; Fri, 23 Aug 2019 06:33:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="XNzBFYZ9"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="Apy+Iem8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404532AbfHWGdN (ORCPT ); Fri, 23 Aug 2019 02:33:13 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:38772 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404523AbfHWGdL (ORCPT ); Fri, 23 Aug 2019 02:33:11 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 528F261157; Fri, 23 Aug 2019 06:33:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1566541990; bh=P4WMJZCUbit61VXbOdXn2Cni0Wq6Y5i5PXty4SNUUdk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XNzBFYZ9jBV/uENkt0i9Pp7Q++M24qUokPrOE0GZHs1rWKVZsyejHDpv7byCh0r1b iQevx8T4OIjD3nhpyOs5brbkWlQTjc2b6AhX4Gj8OW5CsfAISlIzqBVmZlq+zYidwl qVKjm1INlPTd1Z/8QuVkoOvHswiZcQAjhx25teTA= X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.7 required=2.0 tests=ALL_TRUSTED,BAYES_00, DKIM_INVALID,DKIM_SIGNED,SPF_NONE autolearn=no autolearn_force=no version=3.4.0 Received: from blr-ubuntu-41.ap.qualcomm.com (blr-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.18.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: vivek.gautam@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id C24C16110F; Fri, 23 Aug 2019 06:33:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1566541989; bh=P4WMJZCUbit61VXbOdXn2Cni0Wq6Y5i5PXty4SNUUdk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Apy+Iem8BLJ+DCK5hnkAfiAOzInZVJCqWtuqjkn/lYMW3KOuthO+RNMOvuOYnJGT5 7tQQKZgSFLbCYxpcK4XNUadw2HmIX8veNTktDxlr8ckfJiTiVuZH9vujQ5UWMhk8Vg CN8iJABiiNnFLiaCeL9HC6dRUnD/Fc4PxTPADdLs= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C24C16110F Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=vivek.gautam@codeaurora.org From: Vivek Gautam To: joro@8bytes.org, agross@kernel.org, will.deacon@arm.com, robin.murphy@arm.com, iommu@lists.linux-foundation.org Cc: bjorn.andersson@linaro.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Vivek Gautam Subject: [PATCH v4 3/3] iommu: arm-smmu-impl: Add sdm845 implementation hook Date: Fri, 23 Aug 2019 12:02:48 +0530 Message-Id: <20190823063248.13295-4-vivek.gautam@codeaurora.org> X-Mailer: git-send-email 2.16.1.72.g5be1f00a9a70 In-Reply-To: <20190823063248.13295-1-vivek.gautam@codeaurora.org> References: <20190823063248.13295-1-vivek.gautam@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Add reset hook for sdm845 based platforms to turn off the wait-for-safe sequence. Understanding how wait-for-safe logic affects USB and UFS performance on MTP845 and DB845 boards: Qcom's implementation of arm,mmu-500 adds a WAIT-FOR-SAFE logic to address under-performance issues in real-time clients, such as Display, and Camera. On receiving an invalidation requests, the SMMU forwards SAFE request to these clients and waits for SAFE ack signal from real-time clients. The SAFE signal from such clients is used to qualify the start of invalidation. This logic is controlled by chicken bits, one for each - MDP (display), IFE0, and IFE1 (camera), that can be accessed only from secure software on sdm845. This configuration, however, degrades the performance of non-real time clients, such as USB, and UFS etc. This happens because, with wait-for-safe logic enabled the hardware tries to throttle non-real time clients while waiting for SAFE ack signals from real-time clients. On mtp845 and db845 devices, with wait-for-safe logic enabled by the bootloaders we see degraded performance of USB and UFS when kernel enables the smmu stage-1 translations for these clients. Turn off this wait-for-safe logic from the kernel gets us back the perf of USB and UFS devices until we re-visit this when we start seeing perf issues on display/camera on upstream supported SDM845 platforms. The bootloaders on these boards implement secure monitor callbacks to handle a specific command - QCOM_SCM_SVC_SMMU_PROGRAM with which the logic can be toggled. There are other boards such as cheza whose bootloaders don't enable this logic. Such boards don't implement callbacks to handle the specific SCM call so disabling this logic for such boards will be a no-op. This change is inspired by the downstream change from Patrick Daly to address performance issues with display and camera by handling this wait-for-safe within separte io-pagetable ops to do TLB maintenance. So a big thanks to him for the change and for all the offline discussions. Without this change the UFS reads are pretty slow: $ time dd if=/dev/sda of=/dev/zero bs=1048576 count=10 conv=sync 10+0 records in 10+0 records out 10485760 bytes (10.0MB) copied, 22.394903 seconds, 457.2KB/s real 0m 22.39s user 0m 0.00s sys 0m 0.01s With this change they are back to rock! $ time dd if=/dev/sda of=/dev/zero bs=1048576 count=300 conv=sync 300+0 records in 300+0 records out 314572800 bytes (300.0MB) copied, 1.030541 seconds, 291.1MB/s real 0m 1.03s user 0m 0.00s sys 0m 0.54s Signed-off-by: Vivek Gautam --- drivers/iommu/arm-smmu-impl.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/arm-smmu-impl.c b/drivers/iommu/arm-smmu-impl.c index 3f88cd078dd5..0aef87c41f9c 100644 --- a/drivers/iommu/arm-smmu-impl.c +++ b/drivers/iommu/arm-smmu-impl.c @@ -6,6 +6,7 @@ #include #include +#include #include "arm-smmu.h" @@ -102,7 +103,6 @@ static struct arm_smmu_device *cavium_smmu_impl_init(struct arm_smmu_device *smm return &cs->smmu; } - #define ARM_MMU500_ACTLR_CPRE (1 << 1) #define ARM_MMU500_ACR_CACHE_LOCK (1 << 26) @@ -147,6 +147,28 @@ static const struct arm_smmu_impl arm_mmu500_impl = { .reset = arm_mmu500_reset, }; +static int qcom_sdm845_smmu500_reset(struct arm_smmu_device *smmu) +{ + int ret; + + arm_mmu500_reset(smmu); + + /* + * To address performance degradation in non-real time clients, + * such as USB and UFS, turn off wait-for-safe on sdm845 based boards, + * such as MTP and db845, whose firmwares implement secure monitor + * call handlers to turn on/off the wait-for-safe logic. + */ + ret = qcom_scm_qsmmu500_wait_safe_toggle(0); + if (ret) + dev_warn(smmu->dev, "Failed to turn off SAFE logic\n"); + + return 0; +} + +const struct arm_smmu_impl qcom_sdm845_smmu500_impl = { + .reset = qcom_sdm845_smmu500_reset, +}; struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu) { @@ -170,5 +192,8 @@ struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu) "calxeda,smmu-secure-config-access")) smmu->impl = &calxeda_impl; + if (of_device_is_compatible(smmu->dev->of_node, "qcom,sdm845-smmu-500")) + smmu->impl = &qcom_sdm845_smmu500_impl; + return smmu; }